(NaturalNews) It is difficult to imagine a world without onions. These much-loved vegetables, which are the bulbs of the onion plant, have countless uses in the kitchen and are a chief ingredient in many sauces, salads and ethnic dishes. In fact, onions of all types are so popular as secondary ingredients that we often forget that they're nutritional powerhouses in their own right. As this article will prove, however, eating an onion a day (ideally raw) could be one of the most effective and inexpensive ways to safeguard one's health -- especially during wintertime!

Rich in disease-fighting quercetin

Onions, particularly red and yellow onions, are fantastic natural sources of the well-studied flavonoid quercetin. According to the University of Maryland Medical Center, quercetin acts like an antihistamine and an anti-inflammatory, and can guard against heart disease and cancer. (1) These claims are now being proven by research. For example, one study published in Gastroenterology in January 1996 found that eating half of an onion a day could cut the risk of developing stomach cancer by 50 percent. (2) A later study published in the British Journal of Nutrition found that quercetin could significantly reduce the concentrations of LDL cholesterol in overweight subjects, thereby decreasing their risk of cardiovascular disease. (3)

High in allicin

The pungent taste and aroma of onions, as well as their famous release of eye-watering gases when chopped, can be attributed to their allicin content. Also found in garlic, allicin is an organic sulfur compound which, like quercetin, possesses anti-inflammatory properties and can help prevent cancer. Moreover, research featured in Microbes and Infection in 1999 showed that allicin is a potent antimicrobial, antiviral and antibacterial, and can kill common (and increasingly antibiotic-resistant) microbial cultures in the body such as Candida albicans and E. coli. (4) Since viruses thrive in cold weather, eating more onions in winter really is a good idea!

Lower blood sugar

Although the allicin in onions is best-known for treating disease, it has also been linked to reduced blood sugar. A research paper published back in 1975 in Experientia proved that diabetic rabbits that were treated with allicin extracts experienced "significantly reduced" blood sugar levels and glucose-nitrogen ratios. (5) We now know that this is because allicin competes with insulin in the liver, which encourages the body to manufacture more of it. This helps transport glucose through the body, thus reducing blood sugar levels. Additionally, onions are also a top source of chromium, a trace mineral that enhances the actions of insulin. Therefore, diabetic or pre-diabetic individuals can help stabilize their blood sugar levels by adding more allicin-rich foods like onions to their diets.

Surprisingly dense in nutrients

One medium-sized onion also contains a surprising number of additional nutrients. This includes approximately 20 percent of our recommended daily intake of the essential antioxidant vitamin C, as well as varying amounts of protein, fiber, potassium, magnesium, manganese, calcium, iron and most of the B vitamins. Obtaining these nutrients from whole foods like onions is the best way to optimize biosorption rates.

About the author:Michael Ravensthorpe is an independent writer whose research interests include nutrition, alternative medicine, and bushcraft. He is the creator of the website, Spiritfoods, through which he promotes the world's healthiest foods.